防止SSH爆力破解脚本

vim ssh_deny.sh
#!/bin/bash
#Denyhosts SHELL SCRIPT
#2011-04-01
cat /var/log/secure|awk '/Failed/{print $（NF-3）}'|sort|uniq -c|awk '{print $2"="$1;}'  >/root/black.txt
DEFINE="10"
for i in `cat  /root/black.txt`
do
        IP=`echo $i |awk -F= '{print $1}'`
        NUM=`echo $i|awk -F= '{print $2}'`
        if [ $NUM -gt $DEFINE ];
        then
         grep $IP /etc/hosts.deny > /dev/null
          if [ $? -gt 0 ];
          then
          echo "sshd:$IP" >> /etc/hosts.deny
          fi
        fi
done
* */1 * * * root sh /root/ssh_deny.sh